{"id":"CVE-2001-0183","url":"https://www.cyber-defence.io/tools/cve/CVE-2001-0183","generatedAt":"2026-10-27T20:39:31.554Z","title":"ipfw and ip6fw in FreeBSD 4.2 and earlier allows remote attackers to bypass access restrictions by setting the ECE flag in a TCP packet, which makes the packet appear to be part of an established connection.","description":"ipfw and ip6fw in FreeBSD 4.2 and earlier allows remote attackers to bypass access restrictions by setting the ECE flag in a TCP packet, which makes the packet appear to be part of an established connection.","published":"2001-03-26T05:00:00.000Z","lastModified":"2026-06-16T21:53:50.000Z","status":"Modified","sourceIdentifier":"cve@mitre.org","cvss":{"version":"2.0","score":7.5,"severity":"HIGH","vector":"AV:N/AC:L/Au:N/C:P/I:P/A:P"},"cwe":[],"affected":["freebsd/freebsd"],"epss":{"score":0.08094,"percentile":0.9478,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":1,"verified":true,"firstPublished":"2001-01-23","source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[{"edbId":20593,"kind":"exploit","title":"FreeBSD 3.x/4.x - 'ipfw' Filtering Evasion","url":"https://www.exploit-db.com/exploits/20593","sourceUrl":"https://gitlab.com/exploit-database/exploitdb/-/blob/main/exploits/freebsd/remote/20593.txt","file":"exploits/freebsd/remote/20593.txt","published":"2001-01-23","added":"2001-01-23","updated":"2012-08-27","author":"Aragon Gouveia","type":"remote","platform":"freebsd","port":null,"verified":true,"codes":["CVE-2001-0183","OSVDB-1743"],"tags":null,"aliases":null,"applicationUrl":null,"screenshotUrl":null,"referenceUrl":"https://www.securityfocus.com/bid/2293/info"}]},"verdict":{"level":"urgent","text":"A public exploit is published in Exploit-DB (verified) and the impact is high, while EPSS rates exploitation at 8.1%. Anyone can run this; patch or mitigate before the next change window and check exposed instances for signs of use."},"changes":[],"references":[{"url":"ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-01:08.ipfw.asc","tags":["Patch","Vendor Advisory"],"source":"cve@mitre.org"},{"url":"http://www.ciac.org/ciac/bulletins/l-029.shtml","source":"cve@mitre.org"},{"url":"http://www.osvdb.org/1743","source":"cve@mitre.org"},{"url":"http://www.security-express.com/archives/bugtraq/2001-01/0424.html","source":"cve@mitre.org"},{"url":"http://www.securityfocus.com/bid/2293","tags":["Exploit","Patch","Vendor Advisory"],"source":"cve@mitre.org"},{"url":"https://exchange.xforce.ibmcloud.com/vulnerabilities/5998","source":"cve@mitre.org"},{"url":"ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-01:08.ipfw.asc","tags":["Patch","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.ciac.org/ciac/bulletins/l-029.shtml","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.osvdb.org/1743","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.security-express.com/archives/bugtraq/2001-01/0424.html","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.securityfocus.com/bid/2293","tags":["Exploit","Patch","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://exchange.xforce.ibmcloud.com/vulnerabilities/5998","source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2001-0183","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}